A mitochondria-targeting highly specific fluorescent probe for fast sensing of endogenous peroxynitrite in living cells

Peroxynitrite (ONOO⁻), an endogenous reactive oxygen species, acts an important role in various physiological and pathological processes. Herein, we designed a mitochondria targeting fluorescent probe MBTBE for sensitive determination of ONOO⁻. MBTBE exhibits rapid response (< 1 min) and high selectivity towards peroxynitrite with distinct color changing (colorless to orange). The fluorescence intensity at 569 nm was linearly correlated with the concentration of ONOO⁻ (0–10 μM) with a detection limit of 16 nM. Additionally, MBTBE possesses good biocompatibility and mitochondria-targeting. Furthermore, MBTBE was successfully applied to monitor fluctuations in ONOO-levels and H₂S-induced ONOO⁻ clearing in HeLa cells, indicating excellent potential applications in bioanalysis analysis.